That’s the MP aluminum Magnum “Commando” head right?
I don’t have a catalog handy at the moment.
That “Tubed” area looks closer to a Dam. Perhaps time for some seriously off set rockers and re-doing that pushrod tube.
These were not known to flow very well from jump street IIRC from back in the day. Just simply labeled as an upgraded head in aluminum at what ever percentage rate MP said they were over a stock head. 20% comes to mind but that could be horribly wrong.
